Adoptive immunotherapies with tumor infiltrating lymphocytes (TIL) and interleukin-2 (IL-2) can result in tumor regressions in some patients with advanced cancer. However, the use of TIL for some types of cancer has not been possible due to the difficulty in growing TIL from these cancers. Monoclonal antibodies (mAb), though, that are relatively tumor-specific exist for a number of tumor types. By combining variable regions from mAb with T-cell signaling chains, we have designed chimeric antibody/T-cell receptor genes to confer new specificities to gene-modified T-cells. We have demonstrated that T-cells transduced with chimeric receptor genes derived from anti-ovarian and anti-colorectal cancer mAb are activated in response to ovarian and colorectal cancer cells, respectively. In addition, murine T-cells transduced with the anti-ovarian cancer receptor gene are effective in vivo against human ovarian cancer cells, using a nude mouse model, and against murine sarcoma cells transfected with the mAb-defined ovarian antigen gene in C57BL/6 mice. Recently, our lab has defined the culture conditions necessary to gene modify human OKT3- stimulated peripheral blood lymphocytes with chimeric receptor genes. Current efforts are focused on the application of this approach to adoptive immunotherapy trials for colon cancer, ovarian cancer, and breast cancer. Our lab is also pursuing the use of other chimeric receptor genes to improve upon the effectiveness of TIL. Systemic IL-2 therapy is necessary in patients following TIL infusions to maintain TIL viability in vivo. However, IL-2 treatment has dose-limiting systemic toxicities. Therefore, we have constructed chimeric receptors using the extracellular, ligand binding domains from alternative receptors, joined to the cytoplasmic regions from IL-2 receptor chains. We have shown that cytotoxic T-cells (CTL) transduced with receptor genes, consisting of the extracellular domain from the Epo receptor joined to the cytoplasmic regions of the IL-2 receptor beta and gamma chains, proliferate in response to Epo in the absence of IL-2. We hope that TIL transduced with these receptor genes will maintain in vivo viability following stimulation with alternative ligands, such as erythropoietin (Epo), that have less systemic toxicity than IL-2.